Hey
I'm looking for any pointers to figure out if I could replace this IC with another.
The topology can be seen
here. EDIT:
the whole board schematic for reference.
From the service manual about the theory of operation:
Output amplifier A5U2 is a shunt-feedback differential amplifier whose transimpedance converts the current gain of A5U1 (the other proprietary IC on this board) to a voltage gain at the input of the CRT. The CRT's vertical section is the distributed line type with a 330-ohm terminating impedance.
What I'm seeing on the board:
-delay line coming in to the A5 board has stabile voltage (A5U1 input)
-voltage prior to the A5U2 (A5U1 output) is stabile at exactly 28V as stated in manual
-voltage after the A5U2 is unstable between 30V and 50V (should be 40V) - nothing connected to the input of the scope
My question:
-Is it reasonable to assume the input current is stable as the voltage doesn't change?
-Can I replace this IC with something currently available?
Thank you and have a nice day/night
